Categorizing Storage Devices
Storage devices can be categorized as
Magnetic Storage Devices
The most common magnetic storage devices are diskettes, hard disks, high-capacity floppy disks, disk cartridges, and magnetic tape. Magnetic storage devices work by polarizing tiny pieces of iron on the magnetic medium. Read/write heads contain electromagnets that create magnetic charges on the medium. Diskette drives, also known as floppy disk drives, read and write to diskettes. Diskettes are used most often to transfer files between computers, as a means for distributing software, and as a backup medium.
Diskettes are available in size 3.5 inch. Before a magnetic disk can be used, it must be formatted a process that maps the disk's surface and creates tracks and sectors where data can be stored. Hard disks can store more data than diskettes because of their higher-quality media, faster rotational speed, and the tiny distance between the read/write head and the disk's surface.
Optical Storage Devices
The primary types of optical storage are compact disk read-only memory (CD-ROM), digital video disk read-only memory (DVD-ROM), CD-Recordable (CD-R) and CD-Re Writable (CD-RW.
CD-ROM uses the same technology as a music CD does; a laser reads lands and pits on the surface of the disk. Standard CD-ROM disks can store up to 650 MB. Once data is written to the disk, it cannot be changed. DVD-ROM technology is a variation on standard CD-ROM. DVDs offer capacities up to 17 GB. Other popular variations on CD-ROM are CD-Recordable and CD-Re Writable.